Objective: To investigate the probable relationship between the genetic polymorphisms of III collagen α1 (COL3A1) gene and sporadic intracranial aneurysm patients in China of Han nationality. Methods: Peripheral blood samples were collected from 56 randomly selected sporadic intracranial aneurysm patients and 57 control cases without intracranial aneurysm, related risk factors, subarachnoid hemorrhage, and stroke history. Genomic DNA was extracted. PCR and sequencing were performed to evaluate the frequency discrepancy of the single nucleotide polymorphisms (SNPs). After statistical analysis the polymorphism site correlated with intracranial aneurysm was further investigated with bioinformatics methods to explore the influence of the mutations of polymorphic sites on the stability of type III collagen. Results: Both the genotype and allele frequencies of rs1800255 between the intracranial aneurysm and control group were statistically significant. There were no significant differences in the genotype and allele frequencies of thee SNPs rs2271683, rs151446, and nt2346. Data showed that the amino acid change induced by the polymorphism site could sabotage the stability of type III collagen. Conclusion: There is significant correlation between rs1800255 of COL3A1 gene and Chinese sporadic intracranial aneurysm patients of Han nationality, which confirms the COL3A1, gene is one of the susceptible genes of Chinese sporadic intracranial aneurysm patients of Han nationality.